We examine the development of soft X-ray lasers using collisionally pumped Ni-like ions to identify the possibilites for further improvements in the pumping efficiency as we move to shorter wavelengths. The underlying requirements of the pumping system are reviewed. Silver and samarium are examined by detailed simulation in the light of this analysis. It is found that there is significant potential for further reductions in the pump demands for silver using long pre-pulse/mainpulse delays and grazing incidence pumping. Samarium however offers less possibilty of improvement as recombination in the expanding plasma plume inhibits the use of long delays. We find that grazing incidence pumping at an appropriate angle can lead to significant reduction in pump energy.